In my prior U.S. Pat. Nos. 3,968,808, 4,026,313, 4,290,244, 4,437,275, Re. 33,710, 5,230,196 and 5,444,946 I have disclosed interconnected pentagonal, hexagonal, rectangular, or square sections or modules for forming collapsible and expandable portable shelters. The shelters formed by these modules are light in weight and adapted to be quickly put up and taken down. The modules and shelters formed from the modules disclosed in, for example, my U.S. Pat. Nos. 3,968,808 and Re. 33,710 are self-supporting by virtue of a self-locking action resulting from the asymmetrical disposition of certain strut members forming the modules.
My U.S. Pat. Nos. 5,230,196 and 5,444,946 provide systems including modules formed of pivotably pinned pairs of struts arranged on the sides of the modules. The strut pairs are pivotably attached to engageable and disengageable locking devices defining corners of the modules. When the locking devices are disengaged, the modules are adapted to fold into a bundle. When the modules are unfolded, the locking devices are manually engaged to form the expanded modules. The expanded modules including manually engaged locking devices exhibit enhanced resistance to stress-inducing conditions.
My U.S. Pat. No. 5,274,980 discloses a polyhedron building system including a canopy section and telescoping leg assemblies at corners of the canopy. The polyhedron building system is conveniently deployed without tools by persons standing at ground level. The building system is unfolded from a folded condition and, while the leg assemblies are locked in position relative to the components of the canopy but before telescoping the leg assemblies to their full length, the components of the canopy section are locked in place by workers underneath the canopy. Because the canopy has a relatively small pitch, it is a simple matter for workers to reach the components. After the canopy is assembled, the legs are telescoped to their full height.
It is desirable to provide collapsible and expandable folding frame systems that are light in weight, and that exhibit high resistance to stress-inducing conditions. It is further desirable to provide expandable and collapsible folding frame systems that are adapted to be quickly put up at a site without tools, and are adapted to be put up by workers at ground level, without the need for ladders, or other similar equipment. It is further desirable to provide a folding frame system that is easy to store and transport.
In accordance with one aspect of the present invention, a folding frame system is provided. The folding frame system includes a roof assembly including at least three pivotably attached strut pairs, adjacent pairs of the at least three pivotably attached strut pairs defining at least three corners of the roof assembly. The roof assembly is movable between a roof assembly closed position in which struts of the at least three strut pairs are disposed parallel to each other and a roof assembly open position in which struts of the at least three strut pairs are locked in non-parallel positions and ends of the struts of each strut pair of the at least three strut pairs define a rectangle. The folding frame system also includes a folding leg assembly disposed at each of the at least three corners of the roof assembly. Each folding leg assembly includes a leg strut assembly. The leg strut assembly includes a top leg strut and a tubular bottom leg strut in which the top leg strut is telescopingly slidable between a top leg strut closed position and a top leg strut open position. A top end of the top leg strut includes a joint pivotably attaching the top end of the top leg strut to an end of a strut of a strut pair of the at least three strut pairs. The folding leg assembly also includes a lock for locking the top leg strut in the top leg strut open position. The folding leg assembly also includes at least one arm strut assembly. The arm strut assembly is pivotably attached at a bottom end to a point on the bottom leg strut. A top end of the arm strut assembly includes a joint pivotably attaching the top end of the arm strut assembly to at least one strut of the strut pair to which the top end of the top leg strut is pivotably attached.
According to another aspect of the present invention, a folding leg assembly for a folding frame system is provided. The folding frame system includes a plurality of pivotably attached strut pairs. The folding frame system is movable between a folding frame closed position in which struts of the plurality of strut pairs are disposed parallel to each other and a folding frame open position in which struts of the plurality of strut pairs are locked in non-parallel positions and ends of the struts of each strut pair of the plurality of strut pairs define a rectangle. The leg assembly includes at least one leg strut assembly. The leg strut assembly includes a top leg strut and a tubular bottom leg strut in which the top leg strut is telescopingly slidable between a top leg strut closed position and a top leg strut open position. A top end of the top leg strut includes a joint for pivotable attachment to an end of a strut of a strut pair of the plurality of strut pairs of the folding frame system. The leg strut assembly also includes a lock for locking the top leg strut in the top leg strut open position. The leg strut assembly also includes at least one arm strut assembly. The arm strut assembly is pivotably attached at a bottom end to a point on the bottom leg strut. A top end of the arm strut assembly includes a joint for pivotable attachment to the folding frame system.
According to yet another aspect of the present invention, a method for erecting a folding frame system is provided. According to the method, a roof assembly including at least three pivotably attached strut pairs, adjacent pairs of the at least three pivotably attached strut pairs defining at least three corners of the roof assembly, is unfolded from a roof assembly closed position in which struts of the at least three strut pairs are disposed parallel to each other to a roof assembly open position in which struts of the plurality of strut pairs are disposed in nonparallel positions and ends of the struts of each strut pair of the plurality of strut pairs define a rectangle. The roof assembly is locked in the roof assembly open position. After locking the roof assembly in the roof assembly open position, folding leg assemblies disposed at each of the at least three corners of the roof assembly, each folding leg assembly including a leg strut assembly, the leg strut assembly including a top leg strut and a tubular bottom leg strut in which the top leg strut is telescopingly slidable between a top leg strut closed position and a top leg strut open position, a top end of the top leg strut including a joint pivotably attaching the top end of the top leg strut to an end of a strut of a strut pair of the at least three strut pairs, and at least one arm strut assembly, the arm strut assembly being pivotably attached at a bottom end to a point on the bottom leg strut, a top end of the arm strut assembly including a joint pivotably attaching the top end of the arm strut assembly to at least one strut of the strut pair to which the top end of the top leg strut is pivotably attached are unfolded by sliding the top leg strut from the top leg strut closed position to the top leg strut open position. The top leg strut is locked in the top leg strut open position.